package set;

import java.util.HashSet;
import java.util.Set;
import java.util.regex.Pattern;

public class HashSetTest {

    public static void main(String[] args) {
      /*  Set hashSet=new HashSet();
        hashSet.add(23);*/

        System.out.print("123,123".replaceAll(",","").replaceAll(".",""));

        System.out.print(isNumeric("213123a"));
        System.out.print(isNumeric("a213123"));
        System.out.print(isNumeric("2131a23"));
        System.out.print(isNumeric("213123"));
    }
    public static boolean isNumeric(String str){
        Pattern pattern = Pattern.compile("[0-9]*");
        return pattern.matcher(str).matches();

    }
}
